The present invention relates to a technique that can be effectively applied to a medium reading apparatus, such as a compact disk drive device, and more particularly to a technique that can be effectively applied to a medium reading apparatus having as its control device a microcomputer provided with a built-in flash memory (hereinafter to be referred to as a microcomputer with built-in flash memory) capable of erasing data collectively block by block.
In recent years, microcomputers have come to be extensively used as control devices for peripheral units, such as external memories, and for communication apparatuses wherein complex control is required. Especially for optical disk drivers and CD-R drivers, of which new models are introduced every few months, microcomputers with rewritable nonvolatile memories, such as flash memories, are extensively used to meet the need to rewrite the firmware, i.e. the microprogram, of the microcomputer for control use every time a new model is developed.
An example of optical disk driver is shown in FIG. 15 to illustrate the case. In FIG. 15, a reference numeral 400 denotes a personal computer, and 200, an optical disk driver. The personal computer 400 and the optical disk driver 200 are connected by a cable 300, and data are transferred via an interface, such as an AT attachment packet interface (ATAPI) or a small computer system interface (SCSI).
The optical disk driver 200 is provided with, as an electronic component, a control board 260 mounted with a microcomputer 250 in addition to such mechanical components as a spindle motor and an optical pickup. According to the prior art, a wide variety of configurations are available for this control board 260, which may be a microcomputer with built-in flash memory referred to above or a conventional single-chip microcomputer among other things.